This invention relates to 10,11-dihydro-3-carboxycyproheptadine-N-oxide (1-methyl-1-oxo-4-(3-carboxy-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-yl idene) piperdine) as an appetite stimulant and as an antihistaminic agent; also contemplated within the scope of the present invention are the pharmaceutically acceptable salt, ester and amide derivatives of such compound. Further, this invention relates to processes for the preparation of such compounds; to pharmaceutical compositions comprising such compounds; and to methods of treatment comprising administering such compounds and compositions when an appetite stimulant and/or antihistamine effect is indicated. The free acid form of the 10,11-dihydro-3-carboxycyproheptadine-N-oxide of the present invention has the following structural formula (I): ##STR1##
Unexpectedly, it has been discovered that the 10,11-dihydro-3-carboxycyproheptadine-N-oxides of the present invention are appetite stimulants and antihistaminics substantially devoid of other pharmacological effects such as anticholinergic activity, which latter activity is so characteristic of compound structurally related to cyproheptadine, including dihydro derivatives thereof. Accordingly, it is an object of the present invention to provide 10,11-dihydro-3-carboxycyproheptadine-N-oxide and its pharmaceutically acceptable salt, ester and amide derivatives as appetite stimulants and antihistaminic agents. It is a further object of this invention to provide processes for the preparation of such compounds; pharmaceutical compositions comprising such compounds; and methods of treatment comprising administering such compounds and compositions when an appetite stimulant and/or antihistaminic effect is indicated.